"A plenary speaker at the 2006 International Congress of Mathematicians, member of the French Academy of Sciences, often (and probably rightly) described as the world's best lecturer on mathematics, Étienne Ghys is an institution unto himself. As a staunch advocate of promoting research outside the Paris region, he has spent the past twenty years developing the mathematics laboratory at ENS-Lyon. More than anyone else, he is responsible for turning it into one of the leading centers for geometry in the world. Étienne's charisma is matched only by his grumpiness: he has something to say about everything and nothing will stop him from saying it." [Cédric Villani, Birth of a Theorem: A Mathematical Adventure]